Poushali Bhawal

Synthesis and characterization of graphene oxide filled ethylene methyl acrylate hybrid nanocomposites

Graphene oxide (GO) filled ethylene methyl acrylate (EMA) hybrid nanocomposites containing both organic–inorganic features were prepared through a solution mixing method. The morphologies of the graphene oxide within the polymer matrices were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Enhanced dispersion of GO through EMA by exfoliation of the graphene oxide layers were confirmed by X-ray diffraction (XRD) analysis and this value is also supported by the RMS roughness value obtained from AFM analysis. Raman spectroscopy studies revealed the impact of graphene oxide destratification as well as changing of graphene oxide affectivity in the presence of elastomeric media. The physico–mechanical properties of the composites extensively depend on the filler loading, exfoliation of graphene oxide layers, and polymer–filler interaction. Interactions between various oxygen containing groups of chemically derived GO and EMA enhance thermal stability more than pure polymer as shown by thermogravimetric (TGA) and differential scanning calorimetry (DSC) analysis.

Selective cross-linking of carboxylated acrylonitrile butadiene rubber and study of their technological compatibility with poly(ethylene-co-methyl acrlylate) by means of mechanical, thermal, and chemical analysis

Technologically compatible blend becomes an interesting arena of polymer blend industry for their significant properties and fascinating morphologies. This work encompasses the fabrication of technologically compatible blend through melt blending of poly(ethylene-co-methyl acrylate) (EMA) and carboxylated acrylonitrile butadiene rubber (XNBR) in five different ratios to study their compatibility by employing various techniques, like Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA). To observe the reinforcing effect of blend specific amount of metal oxide, zinc oxide (ZnO) was incorporated into the system. Curing characterization, FTIR, and morphological analysis confirm that ZnO selectively forms cross-link with XNBR through the coordination complex and does not show any substantial effect on EMA. DMTA reveals high-temperature relaxation of the carboxylic salt of XNBR phase which reinforces the EMA/XNBRZnO-cross-linked blends and also verified by FTIR analysis. Although DSC shows single glass transition temperature (Tg) for all blend systems in between the Tg of pure polymer component, DMTA confirms the presence of two different Tg for plastic and rubber phases with close proximity, specifying technological compatibility in blend compounds. Increasing XNBR improves tensile strength of blends by sacrificing elongation at break. Therefore, our aim is to tune and optimize the blend features by judicial mixing of EMA and XNBR to mitigate the blend failure during service tenure and develop a novel technologically compatible blend.Graphical abstract

Preparation and Properties of Halloysite Nanotubes/Poly(ethylene methyl acrylate)-Based Nanocomposites by Variation of Mixing Methods

ABSTRACT Halloysite nanotube-based inorganic–organic polymer nanocomposite has been developed with improved mechanical strength in one direction by solution mixing followed by melt mixing. Melt mixing, solution mixing, and melt-cum-solution mixing were performed to optimize the mechanical strength of the nanocomposites. The field emission scanning electron microscopic images and small-angle X-ray scattering spectrum can support the unidirectional array of halloysite nanotubes in the matrix. The tensile properties revealed that solution–melt mixing is the most desired way to develop clay-based nanocomposites. Thermal characterizations implied that thermal stability was improved after nanoclay incorporation. Dynamic mechanical analysis showed the flow properties and the “Payne effect” of the nanocomposites. GRAPHICAL ABSTRACT

Polysaccharide and poly(methacrylic acid) based biodegradable elastomeric biocompatible semi-IPN hydrogel for controlled drug delivery

Nanoparticles embedded semi-interpenetrating (semi-IPNs) polymeric hydrogels with enhanced mechanical toughness and biocompatibility could have splendid biomedical acceptance. Here we propose poly(methacrylic acid) grafted polysaccharide based semi-IPNs filled with nanoclay via in situ Michael type reaction associated with covalent crosslinking with N,N-methylenebisacrylamide (MBA). The effect of nanoclay in the semi-IPN hydrogel has been investigated which showed significant improvement of mechanical robustness. Meanwhile, the hydrogels showed reversible ductility up to 70% in response to cyclic loading-unloading cycle which is an obvious phenomenon of rubber-like elasticity. The synthesized semi-IPN hydrogel show biodegradability and non-cytotoxic nature against human cells. The live-dead assay showed that the prepared hydrogel is a viable platform for cell growth without causing severe cell death. The in vitro drug release study in psychological pH (pH = 7.4) reveals that the controlled drug release phenomena can be tuned by simulating the environment pH. Such features in a single hydrogel assembly can propose this as high performance; biodegradable and non-cytotoxic 3D scaffold based promising biomaterial for tissue engineering.